Interlocking i-beam for roof and side wall structure



April 25, 1961 H. s. DUNN 2,981,333

INTERLOCKING I-BEAM FOR ROOF AND SIDE WALL STRUCTURE Filed May 23, 19602 SheetsSheet l IN V EN TOR.

HAROLD 5. Dunn, BY

9% \A. ATTORNEY April 25, 1961 H. s. DUNN 2,931,383

INTERLOCKING I-BEAM FOR ROOF AND SIDE WALL STRUCTURE Filed May 25, 19602 Sheets-Sheet 2 25% Fisk.

r at INVENTOR. HAROLD 5. DUNN,

BY h g z nh. 1

Arromvev United States Patent INTERLOCKING I-BEAM FOR ROOF AND SIDE WALLSTRUCTURE Harold S. Dunn, 163 Fiesta Way, Fort Lauderdale, Fla.

Filed May 23, 1960, Ser. No. 31,114

4 Claims. (Cl. 189 -36) This invention relates to an interlocking I-beamand 'connecting purlins for roof and vertical wall structures.

The invention contemplates a novel type of I-beam structure that isextruded from suitable metal, such as aluminum and with the I-beamhaving a relatively wide head having depending preferably box-like ribs,a connecting vertical web and a base and with connecting purlins forinterlocking engagement with the flanges of the head portion to preventlateral flexing or bending under abnormal wind conditions and withbrackets that are engaged beneath the purlins and secured to the web ofthe I-beam and with the brackets having a resting engagement upon thelower base of the I-beam whereby to securely anchor the purlins ininterlocking engagement with the I-beam against displacement.

Present current practice for relatively large screened-. in areas hasbeen to employ a split beam construction in roofs for purposes ofprefabrication. A half-beam will be perhaps six and one-half inches deepby one inch wide and is essentially a shallow one inch deep or widechannel on edge in erection as a beam. Two of these open sided channels,fitted together in erection make a hollow beam six and one-half inchesby two inches.

The two half-sections are bolted together at about twelve iinchintervals, both bottom and top throughout their .length. With respect tothe connecting or bracing purlins, these have been previously installedin two ways: (1) by installing interior brackets screwed to the sides ofthe beams to be spaced that is, held together and apart, and then ahollow tube two inches by one inch or a channel of the same size is slidover these brackets and the purlin is then secured by screws to thisbracket; and :(2) by screws through the sides of the half-beams into thescrew slots provided in the interiors of the special two inch by oneinch extruded purlins. Both of these purlin constructions are weak inthat the pull-apart strength is entirely dependent on the grip of thescrews being pulled against in a straight line. In the construction ofthis application, the split beams have been eliminated as they areinherently weak due to the hollow interior. They buckle sideways easilyand creek and groan in the wind.

In the present invention, there has been provided a special form ofextruded I-beam that may be employed to constitute roof rafters orcolumns in forming the side wall areas of an enclosed screened area. Thepurlins are of conventional construction and are notched transversely tohave interlocking engagement beneath the depending flange members of theI-beam in a manner to prevent lateral shifting and with the purlinsbeing additionally supported against movement from their interlockedposition by bracket devices that have a relatively short leg to underliethe purlins and a relatively long leg that is screwed to the side of theweb portion of the I-beam and with the long leg resting upon the base ofthe I-beam. The purlins and the depending flanges of the I-beam havebeen shaped to form spline grooves for the reception of insect screeningthat may constitute either 2,981,383 Patented Apr. 25,- 1961 the roof orthe side walls of the enclosure, such spline connections for the insectscreening being well known in the art. Also, the l-beams when employedas supporting columns for side wall structure is connected to thepurlins and with the purlins being at an elevation to constitute a chairrail, the connections between the purlins and the I-beam being identicalthroughout the structure.

Novel features of construction and operation of the device will be moreclearly apparent during the course of the following description,reference being had to the accompanying drawings wherein has beenillustrated the preferred forms of the device and wherein likecharacters of reference are employed to denote like parts throughout theseveral figures.

In the drawings:

Figure 1 is a sectional view illustrating a pair of parallel adjacentroof forming rafters and the connecting purlins interlocked therewith,

Figure 2 is a fragmentary-top plan view of the device illustrated inFigure 1,

Figure 3 is a composite perspective view illustrating the novel form ofI-beam, the interlocking purlin and the supporting bracket for thepurlin, and

Figure 4 is a section illustrating a slightly modified form of theinvention. 7

Referring specifically to the drawings, there has been illustrated anextruded l-beam section of aluminum or similar material. The I-beam,indicated as a whole by the numeral 5 includes a vertical web portion 6,a base 7 and a relatively wide head 8. The head at its marginal edgeshas been shaped to form downwardly extending substantially squareflanges 9, that are grooved at 10 for the reception of a suitable insectscreening and an attaching spline member, usually formed of vinyl. Thescreen as will be understood, is adapted to form both the roof enclosureand the side wall enclosures.

The several rafters formed by the I-beams 5 are rigidly connectedtogether against lateral flexing, by extruded rectangular purlins 11.The purlins at their tops are provided with the usual spline grooves 12,constituting the fastening means for the several screen panels thatconstitute the roof and the side wall. The purlins 11 adjacent theirfree ends are slotted transversely at 13 and with the slots conformingin dimensions to the flanges 9 whereby the purlins have interlockingengagement with the flanges 9 with the upper surfaces of the purlinsbeing in substantially flush arrangement with the free edges 9' of theflanges 9. The purlins extend between the I-beams 5 and afterinterlocking engagement are supported against disengagement by L-shapedbrackets 14. The brackets 14 have a horizontal short leg portion 15 thatunderlies the bottoms of the purlins 11 to be secured thereto bythreaded fastening devices 16. The long leg 17 of the brackets 14 extenddownwardly to rest upon the base portion 7 of the I-beam 5. The brackets14 are held in tight rigid engagement with the opposite sides of the web6 by threaded fastening devices 18. The brackets 14 have a transversewidth corresponding to the width of the purlins 11.

In the use of this form of the invention, the rafter forming I-beams 5are installed in a predisposed parallel spaced apart relation toconstitute the main supporting elements for the roof. With the I-beams5' in position, the purlins 11 are then installed'by engaging theiropposite ends into interlocking engagement with adjacent flanges 9 atwhich time, the brackets 14 are forced into sup porting engagement withthe bottoms of the purlins and secured to the web portion'6 of theI-beams thus positively holding the purlins against downward movement orpreventing lateral flexing under high wind pressures that mightconceivably dislodge the purlins from their interlocked engagement withthe I-beams. After the structure has been assembled, the various insectscreen panels are installed by engaging the marginal edges of the panelsinto the spline grooves 10 and 12. Where the I-beams constitute thesupporting columns for the roof structure, the purlins 11 are installedin a similar manner and extend from column to column in bracinginterlocking engagement and also constitute a chair rail.

In the form of the invention illustrated in Figure 4, substantiallyidentical structure has been provided, including the I-beams S, the webportion 6, the base 7 and the head 8, having the flanges 9. The purlins,indicated at 11 are also slotted transversely at 13, to haveinterlocking engagement with the flanges 9 at assembly. The purlins attheir lower edges have been additionally slotted transversely at 19 toreceive short vertically arranged leg portions 20 of a modified form ofbracket 21. The brackets 21 have the same short horizontal upper leg 22,carrying the legs 20 and the vertical elongated legs 23, that bear attheir lower ends against the bottom 7 of the I-beam. The legs 22 aresecured to the purlins by threaded fastening devices 24, while the legs23 are securely clamped against the web 6 by threaded fastening devices25. This form of bracket constitutes an additional interlocking meansfor the purlins 11 calculated to prevent any lateral motion of thepurlins with respect to the beams and the purlins for interlockingengagement with both the head 8 and the brackets 21. The forming of theflanges 9 provide channels 26 that snugly receive the ends of thepurlins 11 so that the purlins may engage with the flanges 9 and thechannels 26 in a manner that prevents any disengagement of the purlinswith respect to the I-beams and also provides means to prevent anylateral twisting or flexing of the purlins. In the form of the inventionillustrated in Figure 4, the purlins are initially engaged with theflanges 9 to seat within the channels 26 and to snugly engage theflanges 9, The brackets 21 are then engaged in supporting relation tothe purlins 11 by forcing the brackets 21 laterally to engage the shortlegs 20 into the slots 19 all being in snug and relatively tightengagement after which the brackets 21 are secured to the bottoms of thepurlins and also secured to the opposite sides of the web 6.

It will be apparent from the foregoing that there has been provided avery novel type of extremely rigid roof and wall forming structurescalculated to resist wind stresses and to most efiectively hold therafter forming Lbeams 5 against distortion and to form predeterminedopenings in a roof and wall structure that is subsequently covered bythe insect screen panels. The device is simple in construction, isextremely strong, durable, easily installed and is most effective forproviding a very rigid roof structure. The several parts are quickly andeasily assembled, and the several elements may be formed in anyeconomical manner.

It is to be understood that the invention is not limited to the preciseconstruction shown, but that changes are contemplated as readily fallwithin the spirit of the invention as shall be determined by the scopeof the subjoined claims.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. An interlocking structural device for forming roof and sidewallsupporting members to be covered by insect screen panels, comprisingextruded I-beams that constitute roof rafters and also roof supportingcolumns that are disposed in spaced apart parallel relation, the I-beams having a relatively wide head portion, a base and a connectingweb, the head portion along its marginal edges being downwardly flanged,the flanges being relatively thick transversely and with the flangesbeing provided with upwardly opening spline grooves to receive themarginal edges of insect screen panels, means for bracing the I-beamsagainst lateral twisting that comprises extruded hollow purlins thatextend between adjacent beams, the purlins being provided upon theirupper edges with upwardly opening spline grooves to receive the edges ofthe screen panels, each of the purlins adjacent their opposite endsbeing transversely slotted across their tops and with the slotscorresponding in width to the transverse thickness of the flanges, thepurlins being interlocked with the flanges of adjacent beams through themedium of the engagement of the slots with the flanges, the splinegrooves of the beams and the purlins being disposed at an identicalelevation to receive the marginal edges of the panels and bracket meansconnected with the bottom of the purlins and with the web of the beamsto prevent movement of the purlins downwardly from their interlockedengagement with the flanges.

2. The structure according to claim 1, wherein the flanges of the beamsare substantially square in crosssection and extend for the full lengthof the beams, the downward extension of the flanges forming downwardlyopening channels with the head portion and the web, the said purlinshaving their free ends seated in the channels in assembled relation andto snugly engage the slots with the flanges.

3. The structure according to claim 1, wherein the purlins arerectangular in cross-section, the said supporting brackets being ofL-shape and having a relatively short leg portion that engages beneaththe purlins and with a long leg that is fixedly connected to the web,the lower end of the long leg having a bearing engagement upon the baseof the I-beam.

4. The structure according to claim 1, wherein the purlins upon theirbottoms are transversely slotted, the said brackets being of L-shape andhaving a relatively short upper leg portion and a longer leg portionthat is connected to the web and with its lower end bearing upon thebase, the upper leg portion at its free end having a right angle flangethat is proportioned to engage the last named slots of the purlins.

References Cited in the file of this patent UNITED STATES PATENTS563,530 Wilson July 7, 1896 1,231,564 Carlough et al July 3, 19171,662,766 Wait Mar. 13, 1928 2,097,580 Tarbell Nov. 2, 1937 2,211,384Patterson Aug. 13, 1940 2,617,502 Kessler Nov. 11, 1952 2,897,889Kessler Aug. 4, 1959

